Antenna



FIG. 1 is a front view of an antenna showing our new design;

FIG. 2 is a rear view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a left side view thereof; and,

FIG. 7 is a perspective view thereof.

Broken lines in the drawing views are included to show unclaimed subject matter only and form no part of the claimed design. 

CLAIM The ornamental design for an antenna, as shown and described. 